About 553,000 consumers chose insurance plans through HealthCare.gov between Nov. 1 and Nov. 7, according to federal figures. (Andrew Harnik/AP)

Compared with a year ago, more Americans signed up for health plans during the opening week of the enrollment season on the federal insurance exchange, although the number of first-time customers lagged.

About 553,000 consumers chose insurance plans through HealthCare.gov between Nov. 1 and Nov. 7, according to federal figures.

That volume is almost 20 percent greater than during the first week of enrollment in 2014. The proportion of plan renewals increased, while newcomers fell to about one-third of enrollees from nearly half last year — a decrease of about 37,000 people.

These and other figures are part of a snapshot issued Thursday by Department of Health and Human Services officials that shows how the federal insurance marketplace created under the Affordable Care Act is faring during its third annual sign-up period. The enrollment season continues through January.

The smaller share of newcomers is consistent with recent predictions by federal health officials and outside health-policy experts that attracting additional uninsured Americans to HealthCare.gov would prove more difficult.

HHS Secretary Sylvia Mathews Burwell has said that federal marketing efforts for this enrollment season will focus on the estimated 10.5 million uninsured people who are eligible for coverage through HealthCare.gov because they do not have access to affordable health benefits through a job. HHS officials have estimated that 1 in 4 in that group would sign up for coverage, despite the escalating financial penalties for those who flout an ACA requirement that most individuals carry insurance.

The snapshot suggests that this season’s marketing efforts are making little headway with Hispanics, a group that remains underrepresented among those who purchase insurance through the exchange. The number of people using the Spanish-language version of HealthCare.gov during the first week of November was one-third less than a year ago. The number who contacted a Spanish-speaking representative at one of the federal call centers around the country fell by half — to about 52,000 from nearly 102,000.

In a blog post Thursday, Burwell sidestepped such early enrollment weak spots, writing, “Whether shopping for health insurance for the very first time or re-enrolling in their Marketplace coverage, people are ready to get covered.”

The figures released Thursday cover 38 states now relying on the federal exchange. A dozen states and the District have created separate insurance marketplaces under the law.